Abstract [en]

We have added calculations of PODY for birch, spruce, wheat and potato to theMATCH-Sweden system. Several important updates compared to the previousimplementation for generic crops and generic deciduous trees have been made includingimproved calculations of canopy level ozone concentrations, updated calculations ofquasi-laminar and surface resistance and inclusion of soil moisture dependence forspecific vegetation species.

A comparison to results from the EMEP model for generic crops and generic deciduoustrees shows a better agreement than previously. Considering also that an error in theEMEP calculations has been identified, affecting primarily the PODY calculations forgeneric deciduous trees, MATCH-Sweden and EMEP model results now appear to bemore consistent.Year to year variability of PODY for birch and spruce are similar to that for genericdeciduous trees while numerical values are different, especially for birch, due to differentparameters in the PODY calculation and longer vegetation periods. Critical levelscorresponding to a 4 % growth reduction are exceeded for both birch and spruce in majorparts of Sweden for all years in the period 2013-2017.Year to year variability of PODY for wheat and potato are larger than for generic cropsdue to the higher threshold for PODY used in the calculations. Critical levelscorresponding to a 5 % reduction in crop yield are reached in four of five years insouthern Sweden for wheat and for two in five years for potato.The updated program package for PODY calculations could be used to calculateconsistent time series of PODY for different types of vegetation for the period 1990-2013based on reanalyzed ozone concentrations. The program package could also be developedto calculate PODY for the whole of Europe for different emission- or climate scenarios.The results presented in this report are also available in digital form at the SMHI homepage for environmental monitoring of air quality(www.smhi.se/klimatdata/miljo/atmosfarskemi).